1. Field of the Invention
This invention is related to aerosol compositions comprising highly hydrogenated mineral oil and a method of lubricated gasketed pipes with these compositions.
2. Description of the Related Art
Pipes made of wood, concrete, metal, and plastic for the transportation of water are old in the art. For the transportation of water over long distances, it is common to prepare pipes made of sections of convenient size to be connected together. One common way of connecting pipe segments is the bell and spigot arrangement in which the spigot of one section fits into the bell of the adjoining section. This generally involves inserting the male end of the spigot section into the female end of the bell section to form a tight fit. In order to assure a tight, waterproof seal, it is common to use a flexible gasket in one of the sections, usually the bell section. A lubricant is commonly employed in order to facilitate insertion of the spigot into the bell.
In the laying of pipe sections underground to be used as water pipe, a number of factors must be taken into consideration.
The lubricant must not be toxic to humans as quantities of the lubricant may dissolve in the water and be consumed in drinking water.
The lubricant must be compatible with the pipe and gasket. A lubricant which reacts with and decomposes the gasket and/or the piping material could cause leaks in the system requiring expensive digging and replacement of the piping. A high percentage of gaskets for water pipes is made of butadiene-styrene rubber (SBR), butadiene rubber (BR) and ethylene-propylene copolymers (EPM and EPDM). The Handbook of PVC Pipe; Design and Construction, pages 33 and 47, published by Uni-Bell PVC Pipe Association, Dallas, Tex. (1993) discloses that mineral oil is not compatible with SBR, BR, EPM, and EPDM.
The lubricant should be able to be easily and economically applied. Conventionally, water pipe is laid in trenches which are 2-3 meters deep. The application of lubricant to the gaskets of the pipes usually involves the application of liquid lubricant from an open container with a swab. Under confined working conditions, the open container of lubricant may become spilled or the lubricant may become contaminated. Thus, prior to the present invention, the installer would apply liquid lubricant to the pipe with a brush, rag, or swab. The lubricant would be in an open container which must be held by the installer during application of the lubricant, and then set aside after use. Often, the lubricant container would be set on the edge of the trench with the risk of being spilled or contaminated.
The lubricant should permit ease of installation of the pipes following application. Conventional lubricants allow only a very few seconds for the installer to bring the pieces of pipe into proper alignment.
The problem of spillage, contamination, and waste was addressed by Roux in U.S. Pat. No. 4,641,858. In the Roux patent, the gasket contains a reserve of lubricant which is automatically expelled upon coupling of the pipes. The gaskets of Roux are not economical to produce.
From the above discussion, it is apparent that there remains a need for a lubricating composition which is safe for use in water pipes with regard to ability to be safely ingested by humans and reactivity with the pipes, is economical to produce, is simple to apply and gives the installer adequate time to align the pipe.